Add API extension for cert-manager v1.0.4

[manusa]

Generate Java API client and model types for Kubernetes Cert Manager (x509 certificate management for Kubernetes).

See also:

• https://github.com/jetstack/cert-manager
• https://github.com/jetstack/cert-manager/tree/master/pkg/apis/certmanager
• https://github.com/jetstack/cert-manager/releases/latest

[manusa]

Support was added in:

• https://github.com/manusa/yakc/commit/de352729a7731e857485ac62fc33e44837b9d6ad
• https://github.com/manusa/yakc/commit/9d394309330314b5b7f53537293827e82a76a234
• https://github.com/manusa/yakc/commit/c094e23ca37dc5e0241e3b9bb993010f2af624f3